UB geology professor’s system for rapid soil mapping can lead to more sustainable farming

By Grove Potter

“It’s faster, and you get a higher resolution soil map. We are collecting a lot of data points, many more than with traditional soil sampling.”

Erasmus Oware, assistant professor

Department of Geology

BUFFALO, N.Y. — A University at Buffalo professor has
devised an ingenious way to more quickly test soil in farm fields
to make detailed maps of differing soil types. Those maps can then
be used to design more efficient farming practices.

Erasmus Oware, PhD, assistant professor in the Department of
Geology in the UB College of Arts and Sciences (CAS), has designed
a system to quickly measure the electrical conductivity of every
square yard of a field to determine the boundaries of different
types of soil. Then, a few traditional boring and testing
techniques can ascertain the soil make up of a broad area. The
project is in collaboration with Darcy Telenko, PhD, of the Cornell
Cooperative Extension.​

The method greatly reduces the time to make a soil map —
conventional techniques take a day to map
1 acre, but that time is reduced to 20 minutes with the
new method — and produces a much more detailed map.

“It’s faster, and you get a higher resolution soil
map,” Oware said. “We are collecting a lot of data
points, many more than with traditional soil sampling.”

His method won an $84,840 grant from the New York Farm Viability
Institute, which has been augmented with support from the CAS. The
money was used to purchase the equipment and will help pay for
students to do field work on the project this summer.

Oware’s system involves dragging an electronic wave
emitter behind an ATV that traverses every yard of a field. A
receiver in the vehicle records the conductivity of the soil and
its precise location. The result is a detailed map of the different
soil types, generated with thousands of data points.

Traditional field tests are then performed to determine the
water holding capacity of the different soil types. Knowing how the
soil holds water is crucial in determining how much irrigation and
how much fertilizer is required.

“We will tell the farmer, ‘This part of the field
holds water for a longer time, so you can irrigate it less
frequently. The other area does not hold water, so it needs to be
watered less, but more frequently,’ ” Oware said.

Too much watering can cause several problems.

“If you over-irrigate a farm, the water will either create
runoff and wash the fertilizer into nearby surface water bodies, or
it will induce drainage whereby the fertilizer drains beyond the
root zone and will contaminate groundwater resources,” Oware
said. “On the other hand, under-irrigation will create water
stress of the plant, affecting plant quality and yield.”

Thus, getting a precise handle on irrigation saves water,
reduces the amount of fertilizer used and saves energy, he
said.

“We are trying to design a sustainable and environmentally
friendly way of farming.”

The device measures soil conductivity at 20 and 40 centimeters
deep, the heart of the vegetable “root zone.”

Oware said farmers are eager to participate in his study. One
farm in Niagara County and two farms in Erie County have been
studied, and 12 more are going to be added.

He said farmers know from experience which areas of their fields
produce differently, but the detailed maps give them much more
accuracy and detail as to why.

Once the water needs of a farm field is mapped, the next step is
to modify the irrigation system so that different areas of the
field can be watered at different rates. Oware said he is working
on developing a valve system for that purpose.

Because Oware’s mapping method is so rapid, it can be used
on large, industrial-sized farms, he said. He recently mapped a
seven-acre field in three hours, generating more than 50,000 data
points.